What size torsion bars for a 383 in a 75 Dart?

I have a 451 lowdeck, basically weighs the same as a 383, in my '72 Dart. It was far too mushy with .89" bars. I bought a pair of 1.03" from P-S-T (they may still be giving FABO members a 15% discount, too) and it was a night & day difference. Now the ride is firm but not harsh, and it corners as well as expected (with a big-block in the nose and small tires up front, anyway).